Vacuum skin packaging is a well known technique for packaging food and non-food products in such a way that a tight fitting, often clear package is provided.
Of particular interest is U.S. Pat. No. Re. 30,009 (Perdue et al.) teaching the use of a chamber into which a product to be packaged is brought. The product is supported on an impervious supporting member. A top film is placed over the product, and while in a dome, the top film is brought up against a heated portion of the dome by vacuumization and/or differential air pressure to heat and soften the film, whereupon by release of vacuum and/or vacuumization the heated and softened film drapes over the product and supporting member to form a vacuum skin package.
In the packaging art, it is sometimes desirable to place a product between two sheets of a material which is not heat sealable under normal operating conditions. An example of such a material is metallic foil such as aluminum foil, which provides excellent moisture barrier properties for a moisture sensitive product, but is not readily heat sealable.
When a product placed between two such sheets is to be enclosed between the sheets, it may be necessary to encapsulate the product and sheets in a larger overwrap. Even in such cases, the seams formed by the two sheets of material may not be substantially closed and some or all of the advantages of the use of such material can be lost.
An alternative to an overwrap is the use of a sleeve or other shaped pouch into which the product and pair of sheets may be disposed. This requires of course additional material, additional processing steps and costs, and can still require the use of an overwrap in order to provide a display container or shipping container for the product.
It has now been discovered that materials which are not readily heat sealable, and which can be used in sheet form to sandwich a product therebetween, may be brought together in a substantially closed arrangement by means of the vacuum skin packaging process. At the same time, by the use of such a process, an overall container protects the product enclosed within the sheets, and provides a display container for the product.